About This Weather Station
Note: The National Weather Service revised its wind chill formula effective November 1, 2001. Subsequent wind chill readings are based on the new formula and will be warmer than readings based on the old formula.
The National Weather Service revised its climate extremes reporting period for the Twins Cities Metropolitan Area on February 11, 2008. Temperature extremes are from October 1872 to present and precipitation extremes are from January 1872 to present. The old extremes were from January 1891 to present. Threaded Climate Extret information courtesy of the ThreadEx Project.
- Data are available from November 9, 2000 through today. Wind chill values prior to November 1, 2001 use the old wind chill formula.
- Station location: 44° 48’ 45.14” N, 93° 18’ 38.68” W, altitude 800 feet above Mean Sea Level (as determined by Google Earth).
- Station time zone is Central Time Zone (UTC -0600; during Daylight Saving Time, UTC -0500).
- All temperatures are degrees Fahrenheit (°F), pressures are in/Hg, measurements are inches, speeds in miles/hour.
- Barometric pressure is adjusted to the station altitude and is in inches of mercury (in/Hg) (~+0.8690 in/Hg adjustment).
- Wind run is in miles per day.
- The anemometer is twenty-three feet above ground level, ten feet above roof level. This location has several tall trees surrounding it, so wind speeds are affected.
- Heating the rain gauge consists of using a automobile battery heating pad under ducting insulation for the exterior and a 4 watt holiday light in the interior controlled with a remote controlled outlet. The rain gauge melts precipitation down to at least -20°F and requires 39 watts to operate.
About the Hardware & Software
- The weather station hardware is a Davis Instruments VantagePro 2 (wireless). Data are transmitted by a solar powered radio transmitter broadcasting at between 902 to 928 MHz. The transmitter has a Lithium 3v battery as a backup.
- The web server is an AMD FX-4100 system with 16 Gb DDR3 RAM running 64-bit FreeBSD using Apache web server. Archived data are stored in a MySQL database. Dynamic content is generated using PHP.
- The software used to present the weather information is Virtual Weather Station by Ambient Software (VWS). VWS also comes with several templates for presenting textual and graphical information. It does not require extensive HTML knowledge. The HTML editor I used is Geany.
- Instead of using the stock VWS templates to create HTML files, I created several small templates to create master XML data files. I push several smaller files at every update, and I can be far more creative in using up-to-date information.
- The weather station is attached to an AMD A6-3650 system with 16 Gb DDR3 RAM running Windows 8.1 Professional 64-bit. VWS data are stored on a Samba share hosted on the FreeBSD system.
- Two sections have been added for mobile and WML access. The WML has been tweaked to work with Openwave browser version 4.1, and was tested with Samsung A-460 and Samsung PM-740A phones. The mobile section can be viewed with a text based browser like lynx.